Path: csiph.com!3.us.feeder.erje.net!feeder.erje.net!news.linkpendium.com!news.linkpendium.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: "Nuno Lopes" Newsgroups: comp.compilers Subject: Re: Bounds checking, Optimization techniques and undefined behavior Date: Tue, 7 May 2019 22:38:16 +0100 Organization: Compilers Central Lines: 13 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <19-05-056@comp.compilers> References: <19-04-021@comp.compilers> <19-04-023@comp.compilers> <19-04-037@comp.compilers> <19-04-039@comp.compilers> <19-04-042@comp.compilers> <19-04-044@comp.compilers> <19-04-047@comp.compilers> <19-05-004@comp.compilers> <19-05-006@comp.compilers> <19-05-016@comp.compilers> <19-05-020@comp.compilers> <19-05-024@comp.compilers> <19-05-025@comp.compilers> <19-05-028@comp.compilers> <19-05-029@comp.compilers> <19-05-034@comp.compilers> <19-05-045@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="UTF-8"; reply-type=original Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="28919"; mail-complaints-to="abuse@iecc.com" Keywords: standards, errors Posted-Date: 07 May 2019 18:50:01 EDT X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:2291 Hi, [shameless plug:] Here's a link to the slides of a talk I have last January on undefined behavior (UB) for compiler IRs: http://web.ist.utl.pt/nuno.lopes/pres/ub-vmcai19.pptx The slides have a bunch of examples showing why UB is sometimes useful for compilers, when it is detrimental, or why it's basically impossible to make certain languages fully specified. Nuno